Safe box cutter

Abstract

A box cutter includes a blade, a handle, a sheath and a restraining element. The handle includes a space for receiving a rear portion of the blade, a chamber in communication with the space, a rear slot in communication with the space, and a front slot in communication with the chamber. The sheath is movable in the chamber and covers a front portion of the blade. The restraining element is movable in the handle between a locking position and an unlocking position. In the locking position, the restraining element abuts against the sheath to prevent the sheath from retreating into the handle to keep on covering the front portion of the blade. In the unlocking position, the restraining element is moved from the sheath to allow the sheath to retreat into the handle to allow the front portion of the blade to extend from the sheath.

1 . A box cutter comprising:
 a blade comprising a front portion and a rear portion;   a handle comprising a space for receiving the rear portion of the blade, a chamber in communication with the space, a rear slot in communication with the space, and a front slot in communication with the chamber;   a sheath movable in the chamber, wherein the sheath covers the front portion of the blade;   a restraining element movable in the handle between a locking position and an unlocking position, wherein in the locking position, the restraining element abuts against the sheath to prevent the sheath from retreating into the handle to keep on covering the front portion of the blade, wherein in the unlocking position, the restraining element is moved from the sheath to allow the sheath to retreat into the handle to allow the front portion of the blade to extend from the sheath.   
     
     
         2 . The box cutter according to  claim 1 , wherein the sheath comprises two pair of fins, wherein the handle comprises two pairs of grooves for receiving the pairs of fins. 
     
     
         3 . The box cutter according to  claim 1 , comprising a spring between a portion of the handle and the intermediate portion of the sheath to bias the sheath from the chamber. 
     
     
         4 . The box cutter according to  claim 3 , wherein the sheath comprises a rod inserted in the spring. 
     
     
         5 . The box cutter according to  claim 1 , wherein the sheath comprises:
 two flanks;   the gap extending between the flanks to receive the front portion of the blade; and   an intermediate portion formed between the flanks.   
     
     
         6 . The box cutter according to  claim 1 , comprising a holder for receiving the rear portion of the blade, wherein the handle comprises an insert inserted in the holder. 
     
     
         7 . The box cutter according to  claim 6 , wherein the rear slot is made in the insert, wherein the holder comprises a plate extending in the space via the rear slot. 
     
     
         8 . The box cutter according to  claim 6 , wherein the insert comprises:
 an elastic leaf extending from a rear end of the insert; and   a lock formed at a rear end of the elastic leaf, and   the holder comprising an aperture for receiving the lock.   
     
     
         9 . The box cutter according to  claim 1 , comprising a switch movable on the handle and comprising a connective portion connected to the restraining element, wherein the handle comprises a lateral slot in which the connective portion of the switch is movable. 
     
     
         10 . The box cutter according to  claim 9 , wherein the handle comprises a cavity in communication with the lateral slot, wherein the switch is movable in the cavity. 
     
     
         11 . The box cutter according to  claim 9 , the handle comprises at least one front recess and rear recess in an edge of the slot, wherein the connective portion of the switch comprises at least one boss inserted in the front recess as the restraining element is in the locking position, the boss is inserted in the rear recess as the restraining element is in the unlocking position. 
     
     
         12 . The box cutter according to  claim 8 , wherein the switch is formed with a skid-proof pattern.